LG HVAC Error Code E654

E654 means the LG HVAC system did not receive any switch input signal from the damper motor for 100 consecutive seconds, which represents the time needed for five full rotations. The control board monitors the damper to confirm it is moving correctly, and when no feedback is detected within that window, the system logs this fault. It can point to a loose connector, a wiring issue, a failed motor, or a blocked damper blade.

The E654 fault itself is not an immediate safety hazard, but it does mean the damper is not functioning correctly, which affects airflow control throughout the system. Running the unit in this condition can lead to uneven cooling or heating and potential strain on other components. It is best to address the fault before continuing normal operation.

A power reset may temporarily clear the E654 code from the display, but the error will return if the underlying damper fault has not been corrected. If the damper motor connector is simply loose, reseating it before resetting the unit may resolve the issue permanently. For faults involving a failed motor, damaged wiring, or a bad switch, the code will reappear until the defective component is repaired or replaced.

Start by checking whether the damper motor connector (CN72) is properly seated on the PCB, as a dislodged connector is the most common cause. If the connector is secure, inspect the wiring harness for damage and check that the damper blade can rotate freely without obstruction. If the wiring and blade are both in good condition, the motor or feedback switch may need to be tested for continuity and replaced if faulty.

If the issue is simply a disconnected CN72 connector, there may be no parts cost at all, and a technician visit for diagnosis and reconnection could range from roughly 75 to 150 dollars. If the damper motor or feedback switch needs replacement, parts and labor combined could range from approximately 150 to 450 dollars depending on the specific model and local labor rates. A proper diagnosis is needed before estimating total repair cost.